Ah, that explains a lot. Thanks for that bit of info Jerry.

Actually, I got sidetracked on asking about the official SAR angle in my first post. I didn't originally intend my question to sound like could these be used as a replacement for something like a PLB but I guess that's where my stream of thought took me.

I was originally thinking of using avalanche beacons in a form of "buddy SAR" before calling out the pros. Say you have a bunch of hiking buddies and you already all have avalanche beacons from winter trips together. Then, in the summer, you take a trip together and you take what you think is a quick lone hike away from the cabin or base camp and get lost or injured.

However, sounds like a whistle might be more useful, range-wise, in this circumstance. Or those bubble pack radios you can buy at any big box store.